Trenching machine



Oct. 1, 1929. c. H. KNAUER 1,729,744

TRENCHING MACHINE Filed April 14 1927 3 Sheets-Sheet 1 I N V ENTOR.

I C/y/(mzuer Wk.

A TTORNEY.

1929- c. H. KNAUER TRENCHING MACHINE File April 14 1927 3 Sheets-Sheet 2 Willa/Ill C /7. Knauer 4, 127% ATTORNEY.

BY g- Oct. 1, 1929. c. H. KNAUER 1,729,744

' TRENCHING MACHINE Filed April 14. 1927 3 Sheets-Sheet 5 IN VEN TOR.

' i0 67/ Kvmuer 40 BY I M m ATTORNEY.

Patented Oct. 1, 1929 UNITED STATES PATENT OFFICE CARROLL HUNT KNAUER, OF MUSKEGON, MICHIGAN, ASSIGNOR TO AUSTIN MA- CHINERY CORPORATION, OF MUSKEGON, MICHIGAN, A CORPORATION OF VIR- GIN IA TRENCHING MACHINE Application filed April 14,

This invention relates to improvements in trenching machines of that type in which a series of excavating buckets are included in an endless carrier mounted on a swinging boom. In such machines much trouble is caused by the buckets becoming clogged by the excavated material. In patent to Bentson No. 1,246,527, of November 13, 1917, is disclosed a device for cleaning the buckets while the machine is in operation. In that device a cleaning blade is pivotally mounted in the path of travel of the buckets to dislodge any material clogging the same. A

spring mechanism is provided for normally holding the blade in an initial position to pass through the moving buckets, but which permits the blade to yield to the obstruction until the resistance of the compressed spring forces the blade to dislodge the material. When the material is suddenly released, the blade is snapped back by the spring to its initial position. This continuous snapping back of the blade as the buckets pass, results in considerable wear and tear of the mechanism. Also, the spring mechanism of the patented device is mounted beneath the travel of the buckets where they discharge. As a result, much of the discharged material falls on the spring mechanism, clogging the operation of the same and accelerating the deterioration of the working parts.

The instant invention has for its purpose to improve in certain respects the device of the a patent. One of the objects is to provide a buffer spring to absorb the force of the acute snap back of the blade when the load of an engaged bucket is suddenly dislodged after excessive compression of the spring actuating the blade. Another object is to provide means for mounting the spring mechanism for actuating the cleaning blade above the path of travel of the buckets, so that material dislodged from the buckets cannot fall upon the spring mechanism. Other objects of the instant invention Will be apparent from the following detailed description.

The instant invention consists in the novel construction, combination and arrangement of parts hereinafter described, pointed out in 1927. Serial No. 183,809.

the appended claims, and illustrated by the accompanying drawings:

In the drawings, in which similar reference characters designate corresponding parts:

Figure l is a frontelevation of a bucket cleaner. embodying the invention, showing the ,same mounted in operative position on the boom of a trenching machine; only so much of the boom and associated parts are shown as is necessary to illustrate the invention.

Fig. 2 is a plan view of the bucket cleaner.

Fig. 3 is a detail sectional view, showing the actuating and buifersprings and their connections.

Figs. 4 and 5 are front and side views, showing another modification.

Fig. 6 is a detail sectional view on the line 99 of Fig. 1.

Fig. 7 is a similar view on the line 1010 of Fig. 6.

Referring to the drawings in detail, more particularly to Figs. 1-3 thereof, 10 designates the upper part of the swinging beam or boom that carry the mechanism directly employed in the excavating work of a trenching machine. This mechanism comprises a series of buckets 11, of which only two are shown in vertical section, mounted on an endless carrier formed by sprocket chains 12. As these chains and their is illustrated. The upper bight of each chain 12 is carried by a polygonal sprocket wheel 13 having ,spurs 14 to engage the crossbars connecting the two chains. The peripheral sides of each sprocket wheel are of the same length as the links of the engaged chain to provide a proper driving contact between the two. The sprocket wheels 13 are fast on the shaft 15 journaled in the frame 16, only one side of which is shown, suitably mounted on the upper part of the boom 10. This shaft is driven by the sprocket wheel 17 and the chain 18 leading from a suitable source of power, not shown.

The buckets 11 are mounted at intervals along the chains 12, each bucket being riveted at its sides adjacent to its mouth, as at 18, to opposite links of the chains. Each bucket extends along the link of each chain to which it is directly attached and also along the sucmounting are alike, but one o ceeding link.

The side of the bucket next to the links is open and the opposite side 19 is curved to form a pocket. Owing to the inclination of the bucket during its upward travel along the beam, the outer curved side 19 ofthe bucket practically forms the bottom thereof in carrying the excavated material. The mouth 20 of each bucket, as shown in Fig. 1, is wedge-shaped to form a cutting edge to displace the soil during the trenching operation. As the endless chains pass over the sprocket wheels 13, the polygonal shape of the latter causes the buckets to open outwardly at their lower parts and to drop their loads in the hopper 21, from which the excavated material is discharged onto the endless conveyer 22 to be carried away from the machine.

The foregoing mechanism is well known in the art and forms no part of the present invention, except that certain parts thereof are combined with the novel features particularly described hereinafter.

The bucket cleaning mechanism (Figs. 1-3) comprises the blade 23 mounted in the path of travel of the buckets 11 near the upper end of their flight. The blade is mounted on one of the arms 24 of the bell-crank 25, the other arm 26 of which is journaled at its extremity on the shaft 27 mounted on the upper end of the bracket 28. The shaft 27 is held in place by the clamping plates 29 bolted to the end of the bracket by the bolts 30. The bracket 28 is journaled at an intermediate part on the shaft 15, being held thereon by the bearing complement 31 bolted to the bracket. The bracket 28 is mounted on the under side of the shaft 15 between the two sprocket wheels 13 and extends in a generally horizontal direction across the machine. The lower end of the bracket, when moved toward the right as shown in Fig. 1, tends to engage a flange of the channel iron seated on the upper end of the beam 10. In the lower end of the bracket is a vertical slot 33 (Figs. 6-7) through which projects a lug 34 seated in the adjacent flange of the channel iron. Through the extremity of this lug extends a cotter 35. This connection between the bracket and channel permits limited vertical and lateral play of the bracket with relation to the beam 10.

During the operation of the machine, owing to strain and stress imparted to the parts and the unavoidable looseness in the lit of the bearings and connections, there is a tendency of the shaft 15 to vary its position with relation to the beam 10 to a slight extent and this also affects the position of the bracket 28.

The play permitted between the lower end of.

the bracket and the channel iron 32 allows the bracket to accommodate itself to the relative movement of the beam and the shaft 15.

At the angle of the bell-crank 25 is a hub providing a bearing for the shaft 36 extending therethrough. The ends of the shaft are mounted in the extremities of the arms of the forked head 37, the hub of the bell-crank being positioned between said arms. Threaded in the body of the head 37 is an end of the rod 38 slidable toward its other end through a bearing in the trunnioned member 39. The trunnions of this member are journaled in bearings 40 formed on the upper part of the bracket 41 provided with a flanged base seated on the channel iron 32 on the upper end of the beam 10. Bolts 42 passing through the flanged base of the bracket 41, the channel iron 32 and the angle irons 43 (only one is shown) riveted to the opposite sides of the beam 10, firmly clamp these parts together.

On the inner part of the rod 38 is the main coiled spring 44 interposed between the head 37 and the trunnioned member 39; this spring normally tends to oppose relative movement of the head and trunnioned member toward each other. On the outer part of the rod is the auxiliary spring 45 interposed between the trunnioned member and the nut 46 threaded on the end of the rod. A lock-nut 47 on the extremity of the rod holds the nut 47 against accidental displacement. By adjusting these nuts on the rod the compression of both the main and auxiliary springs can be regulated to meet the requirements of opera tion. The auxiliary spring tends to oppose relative movement of the trunnion member and the nut 46 toward each other.

Extending over the coiled springs 44 and 45 is the protective casing 48, generally rectangular in cross-area and open at its under side. The upper end of the casing is seated on the body part of the forked head 37, being secured thereon by the bolts 49 passing through the sides of the easing into the body part. The lower end of the casing rides on the annular shoulders 50 of the nut 46, the diameter of the shoulder being such as to carry the casing clear of the springs; the cross-section of the interior of the casing is sufliciently large to permit free movement of the springs therein. The sides of the casing, as at 51, are cut away to provide clearance for the trunnioned member during relative movement of said member and the casing.

With the bucket cleaner mounted in place, the blade actuating mechanism is positioned above and to the side of the travel of the buckets at the place where they turn to drop their load. Consequently the discharged material cannot fall on the spring mechanism and its associated parts to clog the operation of the same. When the parts are mounted in assembled relation, the blade 23 is positioned in the path of travel of the buckets 11 so as to pass into the mouth of each bucket just as the latter is turned by the sprocket wheels 13 to drop its load. As the bucket is carried along by the sprocket chain 12 the blade passes through the bucket and clears it of any material that might continue to cling to it.

The radius of the turning movement of the blade is much shorter than that of the curve in Which the bucket travels and the blade is set at such an angle with relation to the travel of the bucket that the edge of the blade is projected forward to lift the material from the bottom and sides of the bucket as well as to push the material from the bucket. Also, the position of the blade is such that the buckets can be run in the reverse direction Without damage to the cleaner mechanism, for there is no point in the movement of the blade where it can contact with the buckets.

Should the load in a bucket be packed therein and difficult to dislodge, which often happens in the. excavation of tough clayey material, the blade on entering the bucket would be forced back, turning the blade and the bell-crank 25 on the shaft 2'7. This movement of the bell-crank moves the head 37 toward the trunnioned member 39. As the trunnioned member is fixed, the spring l-l is-compressed between the abutment-s by said member and the head 37. The resistance of the spring, acting through the intervening mechanism, tends to project the blade through the bucket opposite to the travel of latter. Then the resistance of the compressed spring becomes great enough, the blade will loosen the packed material and force it from the bucket and the expansion of the released spring returns the blade to its initial position. The yielding action of the spring in opposing the movement of the blade prevents to a great extent shock and strain to the cleaner mechanism and at the same time permits full advantage to be taken of the cleaning action on normally loaded buckets. lVhen the main spring is released by discharge of the load from the bucket, should the release be sudden, then the spring would act suddenly to snap back the blade to its initial position. To modify this action of the main spring, the auxiliary spring 45 is provided. This auxiliary spring acts as a butter to absorb the shock of the snap back action of the main spring. The cleaner, as a Whole, is so mounted that practically all the load due to the cleaning operation is transmitted directly to .the boom without affecting that part of the frame supporting the drive shaft of the endless carrier, said frame being less adapted to resist the strains of the cleaner operation than the boom. of the cleaner. should a bucket carry an unyielding obstruction, a rock wedged in the bucket for instance, the cleaning blade could be forced back until the bucket passed without injury to the mechanism.

In Figures 4, and 5, is shown a somewhat modified embodiment of the cleaner, particularly adapted to excavating buckets of large capacity. Instead of a comparatively nar row blade and a single bell-crank c:.=.ri ving the blade, as in the first instance, the 1nodi- In the operation fied form a much Wider blade 52 is employed. This blade is bolted to the flared arms 53 of the opposite bell-cranks 54 having hubs at their angles forming bearings for the ends of the shaft 55. The shaft is mounted in the sleeve 56 formed integrally with the head 57, the sleeve being positioned on the shaft between the two bell-cranks. A set-screw 58 passing through the sleeve 56 and entering the hole 59 in the shaft holds the latter against longitudinal displacement in the sleeve. On the extremities of the shaft are the washers 60 held in place thereon by the cotters 61 outside of the hubs of the bell-cranks. The other arms 62 of the bell-cranks are journaled at their extremities on the shaft 63 mounted on the upper end of the bracket 28, the same as shaft 27 in the first instance. On the ends of the shaft 63 are the washers 64 held thereon by the cotters 65 outside of the bearings at the extremities of the arms 62 of the bell cranks. The head 57 is connected with the other parts of the structure as in the first instance. In operation, the modified form of the blade and its connections act the same as the cleaning blade in the first instance.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the form here inbefore described being merely a preferred embodiment thereof.

lVhat I claim is:

1. In a trenching machine, the combination with a series of buckets included in an endless carrier associated with a support therefor, of a bucket cleaner comprising a lever pivoted at one end to the support, a cleaning blade attached to the other end of the lever in the path of travel of the buckets, an abutment on the support, and a coiled spring between the abutment and an intermediate part of the lever to resist backward movement of the blade passing through the buckets.

2. In a trenching machine, the combination with a series of buckets included in an endless carrier associated with a support therefor, of a bucket cleaner comprising a bell-crank pivoted at the end of one of its arms to the support, a cleaning blade attached tothe other arm of the bell-crank in the path of travel of the buckets, an abutment on the support, and a coiled spring between the abutment and the angle of the bell-crank to resist backward movement of the blade passing through the buckets.

3. In a trenching machine, the combination with a series of buckets included in an endless carrier associated with a support therefor, of a bucket cleaner comprising a lever pivoted at one end to the support, a cleaning blade attached to the other end of the lever in the path of travel of the buckets, an abutment on the support including a guideway, a rod connected with an intermediate part of the lever and slidable through the guideway, and a coiled spring on the rod between the abutment and the lever to resist backward movement of the blade passing through the buckets.

4. In a trenching machine, the combination with a series of buckets included in an endless carrier associated with a support therefor, of a bucket cleaner comprising a bell-crank pivoted at the end of one of its arms to the support, a cleaning blade attached to the other arm of the bell crank in the path of travel of the buckets, an abutment on the support including a guideway, a rod connected with the angle of the bell-crank and slidable through the guideway, and a coiled spring on the rod between the abutment and the bellcrank lever to resist backward movement of the blade passing through the buckets.

5. In a trenching machine, the combination with a series of buckets included in an endless carrier associated with a support therefor, of a bucket cleaner comprising a lever pivoted at one end to the support, a cleaning blade attached to the other end of the lever in'the path of travel of the buckets, a bracket on the support, a trunnioned member having its trunnions journaled in the bracket, a rod connected with an intermediate part of the lever and slidable through the trunnioned member, and a coiled spring on the rod be tween the trunnioned member and the lever to resist backward movement of the blade passing through the buckets.

6. In a trenching machine, the combination with a series of buckets included in an endless carrier associated with a support therefor, of a bucket cleaner comprising a bell-crank pivoted at the end of one of its arms to the support, a cleaning blade attached to the other arm of the bell-crank in the path of travel of the buckets, a bracket on the support, a trunnioned member having its trunnions journaled in the bracket, a rod connected with the angle of the bell-crank and slidable through the trunnioned member, and a coiled spring on the rod between the trunnioned member and the bell-crank to resist backward movement of the blade passing through the buckets.

7 In a trenching machine, the combination with a series of buckets included in an endless carrier associated with a support therefor, of a bucket cleaner comprising a lever pivoted at an end to the support, a cleaning blade attached to the other end of the lever in the path of travel of the buckets, an abutment on the support, a coiled spring between the abutment and an intermediate part of the lever to resist backward movement of the blade passing through the buckets, and a protective casing attached to the lever extending over the spring.

8. In a trenching machine, the combination with a series of buckets included in an endless carrier associated with a support therefor, of a bucket cleaner comprising a bell-crank pivoted at the end of one of its arms to the support, a cleaning blade attached to the other arm of the bell-crank in the path of travel of the buckets, an abutment on the support, a coiled spring between the abutment and the angle of the bell-crank to resist backward movement of the blade passing through the buckets, and a protective casing attached to the angle of the bell-crank extending over the spring.

9. In a trenching machine, the combination with a series of buckets included in an endless carrier associated with a support therefor, of

a bucket cleaner comprising a lever pivoted at an end to the support, a cleaning blade attached to the other end of the lever in the path of travel of the buckets, a head pivoted to an intermediate part of the lever, an abutment on the support, a coiled spring between the abutment and the head to resist backward movement of the blade passing through the buckets, and a protective casing attached to the head and extending over the spring.

10. In a trenching machine, the combination with a series of buckets included in an endless carrier associated with a support therefor, of a bucket cleaner comprising a bell-crank pivoted at the end of one of its arms to the support, a cleaning blade attached to the other arm of the bell-crank in the path of travel of the buckets, a head pivoted to the angle of the bell-crank, an abutment on the support, a coiled spring between the abutment and the head to resist backward movement of the blade passing through the buckets, and a protective casing attached to the head and extending over the spring.

11. In a trenching machine, the combination with a series of buckets included in an endless carrier associated with a support therefor, of a bucket cleaner comprising a lever pivoted at one end to the support, a cleaning blade attached to the other end of the lever in the path of travel of the buckets, a head pivoted to an intermediate part of the lever, an abutment on the support including a guideway, a rod attached to the head and slidable in the guideway, a coiled spring on the rod between the abutment and the head to resist backward movement of the blade passing through the buckets, and a protective casing attached to the head and extending over the spring.

12. In a trenching machine, the combination with a series of buckets included in an endless carrier associated with a support therefor, of a bucket cleaner comprising a bell crank pivoted at the end of one of its arms to the support, a cleaning blade atto the other arm an abutment on ing through tached to the other arm of the bell-crank in the path of travel of the buckets, a head pivoted to the angle of the bell-crank, an abutment on the support including a guideway, a rod attached to the head and slidable in the guideway, a coiled spring on the rod between the abutment and the head to resist backward movement of the blade passing through the buckets, and a protective casing attached to the head and extending over the spring.

13. In a trenching machine, the combination with a series of buckets included in an endless carrier associated with a support therefor, of a bucket cleaner comprising a lever pivoted at one end to the support, a cleaning blade attached to the other end of the lever in the path of travel of the buckets, a head pivoted to an intermediate part of the lever, a bracket on the support, a trunnioned member With its trunnions journaled in the bracket, a rod attached to the head and slidable in the trunnioned member, a coiled spring on the rod between the trunnioned member and the head to resist backward movement of the blade passing through the buckets, and a protective casing attached to the head and extending over the spring to ride on the trunnioned member.

14. In a trenching machine, the combination with a series of buckets included in an endless carrier associated with a support therefor, of a bucket cleaner comprising a bell-crank pivoted at the end of one of its arms to the support, a cleaning blade attached of the bell-crank in the path of travel of the buckets, a head pivoted to the angle of the bell-crank, a bracket on the support, a trunnioned member with its trunnions j-ournaled in the bracket, a rod attached to the head and slidable in the trunnioned member, a coiled spring on the rod between the trunnioned member and the head to resist backward movement of the blade passing through the buckets, and a protective casing attached to the head and extending over the spring to ride on the trunnioned member.

15. In a trenching machine, the combina tion with a series of buckets included in an endless carrier associated with a support therefor, of a bucket cleaner comprising a lever pivoted at one end to the support, a cleaning blade attached to the other end of the lever in the path of travel of the buckets, the support including a guideway, a rod connected with an intermediate part of the lever and slidable through the guideway, a main coiled spring on the rod between the abutment and the lever to resist backward movement of the blade passthe buckets, a stop on the outer end of the rod, and an auxiliary coiled spring on the outer end of the rod between the abutment and the stop to absorb the shock imparted to the rod by release of the main spring previously compressed by backward move- 'ment of the blade.

16. In a trenching machine, the combination with a series of buckets included in an endless carrier associated with a support therefor, of a bucket cleaner comprising a bell-crank pivoted at the end of one of its arms to the support, a cleaning blade attached to the other arm of the bell crank in the path of travel of the buckets, a head pivoted to the angle of the bell-crank, a bracket on the support, a trunnioned member with its trunnions journaled in the bracket, a rod attached to the head and slidable in the trunnioned member, a main coiled spring on the rod between the head and the trunnioned member to resist backward movement of the blade passing through the buckets, a stop on the outer end of the rod, and an auxiliary coiled spring on the outer end of the rod between the stop and the trunnioned member to absorb the shock imparted to the rod by release of the main spring previously compressed by backward movement of the blade.

11 testimony whereof I aflix my signature.

CARROLL HUNT KNAUER 

